Krb5Login Module not in list

Hi,

I am trying to configure Kerberos Authentication on the portal (EP 6 SP15) for SSO.

According to the SAP documentation

"Configuring Login Module Stacks for Kerberos Authentication"

( http://help.sap.com/saphelp_nw04/helpdata/en/12/9f244183bb8639e10000000a1550b0/frameset.htm) step 4, I have to create a login module stack and add the login module's KrbLoginModule and MappingModule to this stack.

However this modules are not in the list of available Login Modules.

Does anyone know how to add these modules to the list?

Thanx,

Twan Janssen